Engine starter



H. T. M. RICE ENGINE STARTER April 7, 1964 ZSheets-Sheet 1 Filed May 1, 1961 R O T N E V m flrrakwsy.

IMO B/CE April 7, 1964 H. T. M. RICE 3,127,884

ENGINE STARTER Filed May 1, 1961 2 Sheets-Sheet 2 INVENTOR. 8 35 HENRY 7: M. RICE United States Patent 3,127,884 ENGINE STARTER Henry T. M. Rice, San Gabriel, (Satin, assignor to Ohlsson & Rice, Inc, Los Angeles, Calif., a corporation of California Filed May 1, 1961, Ser. No. %,689 Claims. (Cl. 123-485) The present invention relates to starting apparatus, and more particularly to starters for internal combustion engines.

An object of the invention is to provide a starter for an internal combustion engine embodying a pawl and ratchet mechanism in which a limitation is placed upon the extent of engagement of the pawl with the ratchet, as well as the extent the pawl moves from engagement with the ratchet upon starting of the engine.

Another object of the invention is to provide a starter for an internal combustion engine embodying a ratchet and pawl engageable therewith, the pawl being pivotally mounted on the engine flywheel, in which the extent of inward movement of the pawl into engagement with the ratchet and its extent of outward disengagement from the ratchet under the action of centrifugal force are positively limited. More specifically, limitations in the extents of inward and outward movements of the pawl are provided by the flywheel itself. I

A further object of the inventionis to provide an improved starter for an internal combustion engine, which is compact and economical to manufacture, and which possesses a long useful life.

Yet another object of the invention is to provide a starter for an internal combustion engine embodying a pawl and ratchet mechanism, in which a spring tends to engage the pawl with the ratchet, the spring and pawl arrangement being a compact one, there being an absence of sharp bends and the like in the spring, th reby minimixing the chance of its fatigue failure and insuring its long useful life. I 1

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a longitudinal section through an engine starter embodying the invention;

, FIG. 2 is a cross-section taken along the line 2-2 on FIG. 1;

FIG. 3 is an enlarged section of the pawl and ratchet mechanism, with the pawl engaging the ratchet;

FIG. 4 is a cross-section similar to FIG. 3 disclosing the pawl disengaged from the ratchet;

FIG. 5 is a section taken generally along the line 5-5 on FIG. 3;

FIG. 6 is a cross-section showing the manner of anchoring the ends of the rewind spring;

FIG. 7 is a perspective view of a pawl.

A starter is illustrated in the drawings for an internal combustion engine, the starter being of the type embodying a starting cord or cable 1% wound upon a suitable reel 11, and a rewind spring 12 for returning the cable to its initial position on the starter reel. As shown in the drawings, an internal combustion engine crankshaft 13 is suitably mounted in a housing or crankcase 14 and extends outwardly therefrom, there being a bearing 15 in the crankcase for rotatably mounting the outer portion of the crankshaft. A flywheel 16 is secured to the outer end of the crankshaft in any suitable manner, as by use of a key 17, the flywheel being held on the crankshaft by a nut 18, or the like, threaded onto the latter.

The flywheel 15 carries a pair of opposed pawls 19, each of which is pivotally mounted on a pin 20 secured to the flywheel. The pawls are engaged by the generally radial teeth 21 of a ratchet wheel 22 suitably fixed to the inner end portion of a sleeve or hub 23 of the starter reel 11, which is rotatably mounted on a stationary hub 24 fixed to an end plate 25 of the frame or housing 26 of the apparatus, as by means of a rivet 27. The reel 11 includes an inner end plate 25- mounted on the inner portion of the sleeve 23 adjacent to the ratchet wheel 22, and an outer plate 29 spaced from the inner plate which bears against a flange 30 on the sleeve or hub 23 and which is suitably secured thereto. A spacer sleeve 31 is disposed on the rotatable hub between the plates 28,

29 to maintain them a correct axial distance apart.

The starting cord or cable It is wound around the reel 11 between its inner and outer plates 28, 29, the inner end of the cord being suitably secured to the outer plate, as by inserting it through a hole 32 in the latter (in a known manner) adjacent to the rotatable hub 23. The coil is wound around the reel, with its outer end 33 extending outwardly therefrom, in a known manner. Upon pulling on the cord, the reel 11 and ratchet wheel 22 are rotated in a proper direction upon the stationary hub 24, the ratchet teeth 21 engaging the pawls 19to rotate the flywheel 16, and thereby turn the crankshaft 13 and initiate starting of the internal combustion engine. When pulling on the starting cord 10, additional energy is stored in the spiral rewind spring 12, the inner end 34 of which is secured to the reel sleeve 23, as by inserting it through a generally radial slot 35 in the latter, with its inner end bent under the inner surface of the sleeve. The outer end 36 of the spiral spring 12 is secured to the enclosing rim portion 37 of the stationary housing 26. As shown, the outer end 36 passes through a generally radial slot or hole 38 in the rim, making a return bend and then passing back through the slot 33, with one end layer lying against the adjacent portion of the spring, as shown in FIG. 6. When thespring 12 is tensioned, it tends to straighten out and pull through the slot 38. This action, however, is resisted by the doubled back end 36 which reinforces the spring. The double thickness of the spring makes a loose fit in the slot 38, allowing the spring to rock in the slot as it is tensioned and then relaxes.

Each pawl 19 is pivoted on a pivot pin 20 and has the main portion 40 of its body lying adjacent to the end face 41 of the flywheel, overlying a hub portion 42 of the flywheel. The tooth portion 43 of each pawl is offset from the main body of the pawl, lying in the same plane as the ratchet wheel 22. The tooth 43 is of the hook type and is adapted to extend over the end of a ratchet tooth 21, with which it is in engagement, there being an inwardly projecting tooth portion 43a engageable with the radial end face 44 of a ratchet Wheel tooth 21.

The pawl tooth 43 is urged inwardly into clutching engagement with the ratchet wheel tooth 21 by a leaf spring 45. This spring has its inner portion 46 bearing against the hub 42 of the flywheel, its outer end 47 being curved or formed as a loop and being received within a companion recess 48 in the pawl to one side of its pivot pin 20, which is the same side of the pivot pin on which the pawl tooth 43 lies. The extent of inward movement of the pawl tooth 43a in engagement with a ratchet tooth 21 is limited and determined by engagement of a stop abutment or nose 49 on the pawl with the flywheel hub 42. When the engine starts and the flywheel 16 rotates at a suflicient speed, centrifugal force will shift or throw the pawl tooth 43 outwardly, the extent of outward movement being limited by engagement of an inwardly directed stop abutment 50 with the spring 45, such abutment having a curved guide surface 51 engaging the leaf spring and progressively bearing on its surface in a direction away from the looped end 47, until the stop abutment 50 bears against the portion 46 of the spring engaging the flywheel hub 42. As centrifugal force throws or urges each pawl out in an outward direction, the leaf spring is curved to a greater extent, as shown in FIG. 4, imparting greater tension thereto, so that upon stopping of the flywheel 16, the leaf spring 45 will move toward a straight position and urge the toothed portion 43 of the pawl in an inward direction, to engage its tooth 43a with a companion tooth 21 on the ratchet wheel 22.

In the operation of the starter, the crankshaft 13 and flywheel 16, are, at first, stationary, the springs 45 urging the tooth portions 43 of the pawls inwardly into engagement with the ratchet wheel teeth 21, such inward extent of movement being limited by contact of the stop abutments or noses 49 of the pawls with the flywheel hub 22. The starting cord occupies its fully wound position on the starter reel 11, the spiral spring 12 having a desired amount of initial tension therein. The starting cord 10 is pulled outwardly to rotate the starting reel 11 and the ratchet wheel 22, such rotation being transmitted through the pawls 19 to the flywheel 16, turning the latter and the crankshaft 13 connected thereto sufliciently to effect starting of the engine. When the engine starts, the flywheel 16 rotates, centrifugal force throwing the toothed portions 43 of the pawls 19 in an outward direction to disengage their teeth 43:: from the ratchet wheel teeth 21. The extent of outward movement of the pawl teeth from the ratchet wheel is limited by the engagement of the outer stop abutment portions 50 of the pawls with the reengaging springs 45 directly behind the points of engagement of the springs with the flywheel hub 42, the pawls remaining in such outer position during the time that the engine is running. The starting cord 10 may be released and the rewind spring 12 will then rotate the reel 11 and ratchet 22 in the opposite direction, to effect a rewinding of the starting cord 10 on the reel, where it is in a position to effect a subsequent restarting of the engine or turning of the crankshaft 13.

It is to be noted that the starter mechanism is compact. The pawls 19 occupy a relatively short axial distance beyond the end face 41 of the flywheel 16, the inward and outward shifting of the pawls being limited by engagement of the stop abutments 49, 40 with the underlying hub portion 42 of the flywheel. The tooth portion 43 of each pawl is offset from the main body 40 sufliciently to engage the ratchet wheel 22, lying in substantially the same plane as the ratchet wheel. The extent of offsetting and the thickness of the ratchet wheel are not very great, so that the overall axial distance occupied by the pawls and ratchet is relatively small, as well as the radial distance that the pawls 19 extend outwardly from the axis of the crankshaft 13. The compact arrangement is further enhanced by the use of the leaf springs 45, end portions 46 of which bear upon the flywheel hub and the outer end portions 47 of which are looped and received in the circular recesses 48 in the pawls. During tensiom'ng of the springs 45, as the result of outward movement of the pawls 19 under the action of centrifugal force, they are not bent in an abrupt manner, the curved surface 51 of each stop abutment 50 merely rolling in a comparatively gradual manner upon the leaf spring, to curve the latter until the abutment 50 is opposite the hub 42 at its point of contact by the leaf spring. The absence of any sharp bends in the springs 45 and their gradual deflection insures against their fatigue failure, and provides their long life. Moreover, the mode of mounting the springs 45 between the pawls 19 and the flywheel hub 22 does not require any additional space, while enabling springs to be used having ample spring force for insuring the reengagement of the pawl teeth 43a with the ratchet teeth 21 when the engine stops.

Not only is the engine starter compact, but it is economical to manufacture. Substantially, all of the parts can be made on a punch press.

I claim:

1. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith; a pawl pivotally mounted on said member; a ratchet wheel engageable with said pawl; means for rotating said wheel to rotate said member; said pawl being subject to centrifugal force acting thereon when rotating with said rotatable member, and due to the mass of the pawl itself, to he disengaged by such force from said ratchet wheel; said pawl and rotatable member having coengageable means thereon for limiting outward movement of said pawl from engagement with said wheel upon starting of the engine and disengagement of said pawl from said ratchet wheel by such centrifugal force.

2. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith; a pawl pivotally mounted on said member; a ratchet wheel engageable with said pawl; means for rotating said wheel to rotate said member; said pawl being subject to centrifugal force acting thereon when rotating with said rotatable member, and due to the mass of the pawl itself, to be disengaged by such force from said ratchet wheel; said pawl having means integral therewith engageable with means on said rotat able member for limiting inward movement of said pawl into engagement with said wheel prior to starting of the engine.

3. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith; a pawl pivotally mounted on said member; a ratchet wheel engageable with said pawl; means for rotating said wheel to rotate said member; said pawl being subject to centrifugal force acting thereon when rotating with said rotatable member to be disengaged by such force from said ratchet wheel; said pawl and rotable member having coengageable means thereon for limiting outward movement of said pawl from engagement with said wheel upon starting of the engine and disengagement of said pawl from said ratchet wheel by such centrifugal force; said pawl having means integral therewith engageable with means on said rotatable member for limiting inward movement of said pawl into engagement with said wheel prior to starting of the engine.

4. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having an offset tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; said pawl having means thereon movable inwardly toward and engageable with said hub for limiting outward movement of said tooth portion from engagement with said ratchet teeth upon starting of the engine.

5. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having an offset tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; said pawl having means thereon movable inwardly toward and engageable with said hub for limiting inward movement of said tooth portion into engagement with said ratchet teeth prior to starting of the engine.

6. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having an offset tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; said pawl having means thereon movable inwardly toward and engageable with said hub for limiting outward movement of said tooth portion from engagement with said ratchet teeth upon starting of the engine; said pawl having means thereon movable inwardly toward and engageable with said hub for limiting inward movement of said tooth portion into engagement with said ratchet teeth prior to starting of the engine.

7. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having a tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; and a leaf spring between and engaging said hub and pawl and urging said tooth portion toward engagement with said ratchet teeth.

8. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having an offset tooth portion; a ratchet Wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; and a leaf spring having an end portion in said pawl and bearing against said hub to urge said tooth portion toward engagement with said ratchet teeth.

9. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having an offset tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; and a leaf spring having en end portion in said pawl and bearing against said hub to urge said tooth portion toward engagement with said ratchet teeth; said pawl having means thereon movable inwardly into engagement with said hub for limiting inward movement of said tooth portion into engagement with said ratchet teeth prior to starting of said engine.

10. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having a tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; and a leaf spring engaging said hub and having a loop portion received in a companion recess in said pawl for urging said tooth portion toward engagement with said ratchet teeth.

11. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having a tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; and a leaf spring engaging said hub and having a loop portion received in a companion recess in said pawl for urging said tooth portion toward engagement with said ratchet teeth; said 'pawl being subject to centrifugal force acting thereon when rotating with said rotatable member to disengage its tooth portion fromsaid ratchet teeth; said pawl having a stop abutment thereon engaging said spring to limit outward movement of said tooth portion from engagement with said ratchet teeth under the action of centrifugal force upon starting of the engine.

12. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having a tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; and a leaf spring engaging said hub and pawl and urging said tooth portion toward engagement with said ratchet teeth; said pawl being subject to centrifugal force acting thereon when rotating with said rotatable member to disengage its tooth portion from said ratchet teeth; said pawl having a stop abutment thereon engaging said spring to limit outward movement of said tooth portion from engagement with said ratchet teeth under the action of centrifugal force upon starting of the engine.

13. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having a tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; and a leaf spring engaging said hub and pawl and urging said tooth portion toward engagement with said ratchet teeth; said pawl being subject to centrifugal force acting thereon when rotating with said rotatable member to disengage its tooth portion from said ratchet teeth; said pawl having a stop abutment thereon having a curved face progressively bearing upon an increasing length of said spring as said pawl swings outwardly upon starting of the engine to limit outward movement of said tooth portion from engagement with said ratchet teeth under the action of centrifugal force.

14. In a starter for an internal combustion engine: a rotatable member adapted to be connected to the engine to rotate therewith and having a hub; a pawl pivotally mounted on said member outwardly of said hub and having an offset tooth portion; a ratchet wheel adjacent to said rotatable member and having teeth engageable with said tooth portion; a leaf spring engaging said hub and having a loop portion received in a companion recess in said pawl for urging said tooth portion toward engagement with said ratchet teeth; said pawl having means thereon engageable with said hub for limiting inward movement of said tooth portion into engagement with said ratchet teeth prior to starting of the engine; said pawl being subject to centrifugal force acting thereon when rotating with said rotatable member to disengage its tooth portion from said ratchet teeth; said pawl having a stop abutment thereon provided with a curved face progressively bearing upon an increasing length of said spring as said pawl swings outwardly upon starting of the engine to limit outward movement of said tooth portion from engagement with said ratchet teeth under the action of centrifugal force.

15. In combination with an internal combustion engine having a crankshaft and a flywheel secured to said crankshaft, said flywheel having a hub; stationary supporting means surrounding said crankshaft; a pawl pivotally mounted on said flywheel outwardly of said hub and having an offset tooth portion; a starter reel rotatably mounted on said supporting means; a ratchet wheel 7 secured to said starter reel adjacent to said flywheel and having teeth engageable with said tooth portion of said pawl; a starter cord wound on said starter reel for rotating said reel and ratchet wheel; spring means secured to said starter reel and stationary means to rewind the starting cord on said reel; a leaf spring engaging said hub and having an end portion in said pawl for urging said tooth portion toward engagement with said ratchet teeth; said pawl having means thereon engageable with said hub for limiting inward movement of said tooth portion into enpawl having a stop abutment thereon provided with a 15 8 curved face progressively bearing upon an increasing length of said spring as said pawl swings outwardly upon starting of the engine to limit outward movement of said tooth portion from engagement with said ratchet teeth 5 underthe action of centrifugal force.

References Cited in the file of this patent UNITED STATES PATENTS Gilbert et a1. June 2, 1953 

1. IN A STARTER FOR AN INTERNAL COMBUSTION ENGINE: A ROTATABLE MEMBER ADAPTED TO BE CONNECTED TO THE ENGINE TO ROTATE THEREWITH; A PAWL PIVOTALLY MOUNTED ON SAID MEMBER; A RATCHET WHEEL ENGAGEABLE WITH SAID PAWL; MEANS FOR ROTATING SAID WHEEL TO ROTATE SAID MEMBER; SAID PAWL BEING SUBJECT TO CENTRIFUGAL FORCE ACTING THEREON WHEN ROTATING WITH SAID ROTATABLE MEMBER, AND DUE TO THE MASS OF THE PAWL ITSELF, TO BE DISENGAGED BY SUCH FORCE FROM SAID RATCHET WHEEL; SAID PAWL AND ROTATABLE MEMBER HAVING COENGAGEABLE MEANS THEREON FOR LIMITING OUTWARD MOVEMENT OF SAID PAWL FROM ENGAGEMENT WITH SAID WHEEL UPON STARTING OF THE ENGINE AND DISENGAGEMENT OF SAID PAWL FROM SAID RATCHET WHEEL BY SUCH CENTRIFUGAL FORCE. 